Django | Delete records in Django models
Delete query performs an SQL delete query on all rows in the queryset and returns the number of objects deleted and a dictionary with the number of deletions per object type.
Delete from an instance
customer = Customer.objects.all().get('customer_id'=5)
customer.delete()
OR
Customer.objects.get('customer_id'=5).delete()
The get() query raises an exception if the object does not exist because at first, it tries to retrieve the specified object and then performs a delete operation.
To delete it directly:
customer = Customer.objects.filter('customer_id'=5)
customer.delete()
OR
Customer.objects.filter('customer_id'=5).delete()
this does not raise any exception if the object does not exist and it directly produces the query
DELETE FROM Customer where customer_id=5
Delete all instance
Customer_all= Customer.objects.all()
Customer_all.delete()
OR
Customer.objects.all().delete()
Tips and Tricks
Python In-place swapping of two numbers
Python | In-place swapping of two numbers
>>> a, b = 10, 20
>>> print(a, b)
10 20
>>> a, b = b, a
>>> print(a, b)
20 10
Reversing a String in Python
Python | Reversing a String
>>> x = 'PythonWorld'
>>> print(x[: : -1])
dlroWnohtyP
Python join all items of a list to convert into a single string
Python | Join all items of a list to convert into a single string
>>> x = ["Python", "Online", "Training"]
>>> print(" ".join(x))
Python Online Training
python return multiple values from functions
Python | Return multiple values from functions
>>> def A():
return 2, 3, 4
>>> a, b, c = A()
>>> print(a, b, c)
2 3 4
Python Print String N times
Python | Print String N times
>>> s = 'Python'
>>> n = 5
>>> print(s * n)
PythonPythonPythonPythonPython
